HIGH-STRENGTH STEEL SHEET, HIGH-STRENGTH GALVANIZED STEEL SHEET, AND METHOD FOR MANUFACTURING SAME
Provided are a high-strength steel sheet and a high-strength galvanized steel sheet having a tensile strength of 980 MPa or more and excellent bending workability and methods for manufacturing these steel sheets. A high-strength steel sheet has a specified chemical composition, in which a Mn-segrega...
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Main Authors | , , , , |
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Format | Patent |
Language | English French German |
Published |
04.11.2020
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Subjects | |
Online Access | Get full text |
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Summary: | Provided are a high-strength steel sheet and a high-strength galvanized steel sheet having a tensile strength of 980 MPa or more and excellent bending workability and methods for manufacturing these steel sheets. A high-strength steel sheet has a specified chemical composition, in which a Mn-segregation degree in a region within 100 µm from a surface of the steel sheet in a thickness direction is 1.5 or less, in a plane parallel to the surface of the steel sheet in a region within 100 µm from the surface of the steel sheet in the thickness direction, the number of oxide-based inclusion grains having a grain long diameter of 5 µm or more is 1000 or less per 100 mm 2 , a proportion of the number of oxide-based inclusion grains having a chemical composition containing alumina in an amount of 50 mass% or more, silica in an amount of 20 mass% or less, and calcia in an amount of 40 mass% or less to the total number of oxide-based inclusion grains having a grain long diameter of 5 µm or more is 80% or more, a specified metallographic structure, and a tensile strength of 980 MPa or more. |
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Bibliography: | Application Number: EP20160881723 |